From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2FEAC65BAE for ; Thu, 13 Dec 2018 21:16:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8D7B820851 for ; Thu, 13 Dec 2018 21:16:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544735811; bh=nLgYKe0mxM+7leaWOp77dt2fMSBjBORgDYMe6PEwuL0=; h=From:To:Subject:Date:List-ID:From; b=COVcb/WYkVk0hjpO8VpDItzVZMNJ86oozc+vs5EIZtXi9xfp9JYuIQMh4vUFqaE0v 4qlV8eDydKL8r2/fcDrw8mWk8PwIdfuB7MSQhktvPeoX7pX2A+PYTR6SWVqwZO+9fs YlYfyJqocfxZUq5MmszAo654Yu4Bg5DpoqR6B6mA= DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D7B820851 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727455AbeLMVQu (ORCPT ); Thu, 13 Dec 2018 16:16:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:47674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726461AbeLMVQu (ORCPT ); Thu, 13 Dec 2018 16:16:50 -0500 Received: from localhost.localdomain (bl8-197-74.dsl.telepac.pt [85.241.197.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 29EF820851 for ; Thu, 13 Dec 2018 21:16:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1544735809; bh=nLgYKe0mxM+7leaWOp77dt2fMSBjBORgDYMe6PEwuL0=; h=From:To:Subject:Date:From; b=iM7Xd+e3eM5IfQADGBzWCK3isnrTFYTAjpphdNoyIhWrmJbdfiVnwdjIsiWx78iIU nayWA8CQrJ6ESTUGOH2KQPYTy43Q9ccNkoIedHSAlqYjDufWTN4ROp8PvH6cvCigYH gNStaWU4LzUMpVa0S4r3crszMIyM/ZfP9SlngCHo= From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH] Btrfs: setup a nofs context for memory allocation at btrfs_create_tree() Date: Thu, 13 Dec 2018 21:16:45 +0000 Message-Id: <20181213211645.14713-1-fdmanana@kernel.org> X-Mailer: git-send-email 2.11.0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Filipe Manana We are holding a transaction handle when creating a tree, therefore we can not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is triggered by the allocation, therefore setup a nofs context. Fixes: 74e4d82757f74 ("btrfs: let callers of btrfs_alloc_root pass gfp flags") Signed-off-by: Filipe Manana --- fs/btrfs/disk-io.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 67afeaf28a41..3e1b846156dd 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include "ctree.h" #include "disk-io.h" @@ -1235,10 +1236,17 @@ struct btrfs_root *btrfs_create_tree(struct btrfs_trans_handle *trans, struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root *root; struct btrfs_key key; + unsigned int nofs_flag; int ret = 0; uuid_le uuid = NULL_UUID_LE; + /* + * We're holding a transaction handle, so use a NOFS memory allocation + * context to avoid deadlock if reclaim happens. + */ + nofs_flag = memalloc_nofs_save(); root = btrfs_alloc_root(fs_info, GFP_KERNEL); + memalloc_nofs_restore(nofs_flag); if (!root) return ERR_PTR(-ENOMEM); -- 2.11.0